This invention relates to gas turbine engines. More specifically, it relates to an assembly for bridging gaps between adjacent airfoils in rotor or stator stages of gas turbine engines. The invention is particularly suited to seals with circumferential spacers in a fan stage of an engine, but it may equally well be applied in other parts of the engine.
Conventionally a fan rotor stage in a gas turbine engine comprises a plurality of radially extending fan blades mounted on a rotor. The blades are mounted on the rotor by inserting the inner end of the blade in a correspondingly shaped retention grooves disposed about the rotor. Circumferential spacers bridge the gaps between adjacent blades to define gas path that provides thrust for an aircraft.
A resilient seal is placed between the circumferential spacers and the adjacent fan blades. The seal may protrude to abut the adjacent fan blades and seal the gaps to prevent gas from leaking between the circumferential spacers and the blades.
A large number of seal designs are known, including solid rubber seals, bellows seals, brush seals, compressible tube seals and composite seals with a rubber tip. Solid rubber seals may be heavy, the rubber tips of the composite seals are prone to debonding, and bellows seals are prone to severe erosion because the bellows sits close to the airstream.